Echocardiography is the main non-invasive screening tool for pulmonary hypertension (PH) in sickle cell disease (SCD), but relies mostly on the tricuspid regurgitation velocity (TRV) assessment, without distinction between pre- and post-capillary patterns. Using Etendard Cohort data, the aim of this study was to refine echocardiographic assessment of PH in SCD patients.

The French Etendard Study is a prospective cohort initially designed to assess the prevalence of PH among 398 SCD participants. We analysed echocardiography data of the 96 Etendard patients who underwent Right Heart Catheterisation (RCH), because of a TRV≥2.5m/s, and compared them to invasive haemodynamic measurements.

PH was found in 24/96 patients with 11 precapillary and 13 post-capillary. In addition to TRV, multivariate analysis identified indexed left atrial volume (LAV_ind) and lateral E’ wave velocity (E’lat) as independent echocardiographic predictors of PH (OR=1.06 and 0.6, respectively, P<0.01). They both had good accuracy to predict PH with an optimal cut-off of 48mL/m² for LAV_ind (AUC=0.78, Se=81% and Sp=75%) and 12cm/s for E’lat (AUC=0.8, Se=72% and Sp=79). Using the association of a TRV≥3m/s or a TRV [2.5; 2.9] m/s with LAV_ind>48mL/m² and E’lat<12cm/s, we could predict PH with a PPV of 68% and NPV of 90%.

Moreover, comparing echocardiography data of pre- and post-capillary PH patients, we observed that pulmonary acceleration time (PAcT) was different in the two groups (104±22ms vs. 160±21ms, P<0.001) with an excellent accuracy for the differentiation of both phenotypes (AUC=0.95, optimal cut-off=115ms, Se=100% and Sp=78%).

Echocardiography can accurately estimates the probability of PH in SCD patients with an integrated approach using TRV, LAV_ind and E’lat. In addition, among patients with suspected PH, measuring PAcT as a surrogate of PVR allows a good differentiation between pre and post-capillary phenotypes.